The present invention relates to a tapping apparatus having a drilling device for producing an outlet on a medium-carrying pipeline, on which a tapping fitting is arranged, and having a drive and advance device for driving and advancing a drilling tool.
In pipeline construction, in particular in communal pipeline construction, the supply systems for water and gas are laid underground. In the districts which are built over with dwelling units, the main pipelines of the system are first laid along the main roads, and, depending on the advance of the superstructure, the secondary lines to the side roads and the service connections are connected as branches. For the operation of the main pipeline, it is advantageous that the main pipeline, after the construction of the branches, can remain in the operable state, that is to say carrying medium and under operating pressure. For smaller pipe diameters, tapping fittings in combination with outlet connecting pieces and valves and with simple tapping apparatuses which are to be used only once are known.
DE-A-38 38 435 discloses a tapping apparatus of the generic type for gas lines under pressure. The tapping apparatus consists of a universal drilling tool which is connected to a drill stem which is surrounded by a hollow shaft over its entire length. The hollow shaft is in turn surrounded by a multi-piece sleeve. The sleeve parts are screwed to one another and have different thread pitches. Individual sleeve parts can be coupled to the hollow shaft and the drill stem. The coupling functions with springs, tooth systems or friction linings. The different pitch enables different materials to be tapped with a single drilling tool. The use of this drilling apparatus in the case of pipelines under pressure requires the presence of a valve or a gate over the location to be tapped on the main pipeline. A wrench is necessary for driving the drill stem.
Accordingly, it is the principle object of the present invention to provide a tapping apparatus having a drilling device for producing an outlet on a medium-carrying pipeline, wherein the tapping apparatus is constructed such that it is especially easy to operate and can also be used with relatively large pipeline diameters.
The foregoing object is achieved by providing a tapping apparatus having a drilling device for producing an outlet on a medium-carrying pipeline, on which a tapping fitting is arranged, and having a drive and advance device for driving and advancing a drilling tool, a coupling and uncoupling mechanism being arranged for coupling and uncoupling the drive device to and from the advance device for the drilling tool.
It is advantageous that the tapping apparatus is as light as possible and has as far as possible small dimensions. The smaller the dimensions and the lighter the weight of the apparatus, the simpler it is to transport the apparatus from site to site. A tapping apparatus having a small overall length is advantageously used in trenches in which the main line has to be tapped laterally and branched off to the side. For the construction of the trench, excavating work, which is expensive and always leaves behind ugly traces on the road surface, can be saved. This is achieved by virtue of the fact that a base frame which can be detachably connected and is arranged essentially parallel to the pipeline is formed, an exchangeable and essentially cylindrical passage part, which can be connected to the tapping fitting, for the drilling tool being arranged between the base frame and the pipeline, and that a drill stem is provided for the interchangeable connection between the drilling tool and the drive and advance device. This is also achieved by the base frame being arranged such that it can be detachably connected to the pipeline by means of clamping straps, the base frame having a clamping device having a fine adjustment for the clamping straps.
It is also advantageous that the tapping apparatus can alternatively be used in pressureless pipelines and in pipelines under pressure. This is achieved by the exchangeable passage part being alternatively designed as a distance piece or as a shut-off device. This is also achieved by the shut-off device being designed as a ball valve or a slide.
It is also advantageous that the same tapping apparatus can be used in the case of pipeline diameters of different size. This is achieved owing to the fact that the tapping apparatus is of modular construction and in particular can be dismantled into individual parts, such as base frame, passage part, drill stem, drilling tool and drive and advance device, and can be transported as such.